Apparatus and method of zero clearance connection with optional sensing function

ABSTRACT

Apparatus and method for mechanically attached connections of conduits may include a conduit gripping member ( 34 ), a drive member ( 36 ), and a seal member ( 48 ), the drive member ( 36 ) causing axial movement of the conduit gripping member ( 34 ) to indent into an outer surface of the conduit when the assembly is pulled-up, the drive member ( 36 ) causing the seal member ( 48 ) to form a zero clearance seal at a location that is axially spaced from the conduit gripping member ( 34 ). The zero clearance seal may comprise a face seal arrangement including a gasket ( 48 ), and the conduit gripping member ( 34 ) may be a ferrule, ring or other device that can grip and optionally seal against the conduit outer surface. The assembly may include an optional sensing function for detecting or sensing a characteristic or condition of an assembly component or the fluid or both.

The present application claims the benefit of the following U.S. Provisional patent applications: U.S. provisional application Ser. No. 60/937,277, filed on Jun. 26, 2007, entitled Smart Fittings, U.S. provisional application Ser. No. 61/040,187, filed on Mar. 28, 2008, entitled Apparatus and Method of Zero Clearance Connection, and U.S. provisional application Ser. No. 61/040,178, filed on Mar. 28, 2008, entitled Apparatus and Method of Zero Clearance Connection with Sensing Function, the entire disclosures all of which are fully incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates to mechanically attached connections such as fittings, joints, couplings, unions and so on that are used in fluid systems or fluid circuits to contain fluid flow and fluid pressure. Such mechanically attached connections may be used with but are not limited to conduit fittings for tube, pipe or any other type of conduit, and that connect a conduit end to either another conduit end or to another portion, element or component of a fluid system. For simplicity and clarity, the term ‘fitting’ as used herein is intended to be all inclusive of other terms, for example coupling, connection, union, joint and so on, that could alternatively be used to refer to a mechanically attached connection. Such mechanically attached connections are characterized by a fluid tight seal and mechanical strength to hold the connection together including sufficient grip of the conduit under vibration, stress and pressure. Fluids may include gas, liquid, slurries and any variation or combination thereof.

Fluid systems and circuits typically use mechanically attached connections to interconnect conduit ends to each other and to flow devices which may control flow, contain flow, regulate flow, measure one or more characteristics of the fluid or fluid flow, or otherwise influence the fluid within the fluid system. Fluid systems are found everywhere, from the simplest residential plumbing system, to the most complex fluid systems for the petrochemical, semiconductor, biopharmaceutical, medical, food, commercial, residential, manufacturing, analytical instrumentation and transportation industries to name just a few examples. Complex systems may include thousands of fittings, either fittings being installed as a new installation or as part of repair, maintenance or retrofit operations, or fittings that were previously installed.

The term ‘mechanically attached connection’ as used herein means any connection for or in a fluid system that involves at least one connection that is held in place by mechanically applied force, stress, pressure, torque, or the like, such as, for example, a threaded connection, a clamped connection, a bolted or screwed connection and so on. This is distinguished from a metallurgical or chemical connection most commonly practiced as welding, brazing, soldering, adhesive and so forth. A mechanically attached connection may include a combination of mechanical and metallurgical connections, and often does, and such connections are also within the term ‘mechanically attached connections’ as they include at least one such connection.

SUMMARY OF THE DISCLOSURE

In accordance with one of the inventions presented in this disclosure, a zero clearance fitting or assembly for a conduit mechanically attached connection is provided. In one embodiment, a fitting for conduit connection may include a conduit gripping member that optionally indents into an outer surface of the conduit, and may optionally seal against that outer surface. In another embodiment, the fitting further includes a seal element that forms a zero clearance seal that is axially spaced from the conduit gripping indentation. In still a further embodiment, a seal element is disposed between a facing surface of a face seal member and a face seal surface on another facing surface. In a more specific exemplary embodiment, the seal element comprises a gasket axially compressed between two facing surfaces. In another embodiment, the conduit gripping member and seal arrangement, and in some cases additional parts, may optionally be held together as a separate subassembly or preassembly.

In accordance with another invention presented in this disclosure, a mechanically attached connection for conduits is contemplated that includes a zero clearance seal as part of a zero clearance fitting or assembly for conduit connection, along with a sensing function that is integrated or incorporated into one or more parts of the fitting. In an exemplary embodiment, a sensing function may be included or associated with a seal element that is also used to provide a zero clearance seal in the assembly. In a more specific exemplary embodiment, the sensing function may be realized in the form of a sensor or device that is embedded, attached, integrated or otherwise incorporated with or associated with the seal element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an embodiment of a fitting incorporating one or more inventions disclosed herein, illustrated in longitudinal cross-section, with the parts assembled in a finger-tight condition;

FIG. 2 is an enlarged view of the circle A region in FIG. 1;

FIG. 3 is an enlarged view of the circled region of FIG. 2;

FIG. 4 is an enlarged view of the circle B region in FIG. 1;

FIG. 5 is an enlarged illustration of the fitting of FIG. 1 in a completed pulled-up condition, illustrated in half-longitudinal cross-section;

FIG. 6 is another embodiment of the assembly illustrated in FIGS. 1 and 2, including a sensing function in accordance with another invention disclosed herein;

FIG. 7 illustrates an example of a flareless ferrule type fitting in a finger tight condition including a sensing function;

FIG. 8 is another embodiment of a zero clearance fitting, illustrated in longitudinal cross-section, with the parts assembled in a finger-tight condition;

FIG. 9 is an enlarged illustration of the fitting of FIG. 8 in a completed pulled-up condition, illustrated in half-longitudinal cross-section;

FIG. 10 is an enlarged illustration of the circled region A of FIG. 8;

FIGS. 11-15 illustrate additional alternative embodiments of zero clearance fittings.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Although the various embodiments are described herein with specific reference to a tube fitting, and more specifically to a tube fitting for stainless steel tubing, those skilled in the art will readily appreciate that the inventions herein may be used with any metal or non-metal conduit and any metal or non-metal fitting components, including but not limited to plastics, polymers and so on. The inventions may also be used with thinner walled conduits or thicker walled conduits. As used herein, the term ‘zero clearance’ refers to an arrangement by which a fitting that has been previously attached to a conduit end and connected to another fluid member, such fitting may be loosened to allow separation of the conduit end from the other fluid member, without requiring axial displacement of the conduit end. In a more general concept, a zero clearance fitting facilitates disassembly of the fitting so that the fitting may be separated without requiring axial displacement of the conduit end that is attached to the fitting. For example, a zero clearance fitting that includes a zero clearance seal may allow separating of a first coupling component—for example a nut—from a second coupling component—for example a body—to permit the conduit end to be disconnected from the other fluid member, with a simple radial movement or displacement. Moreover, while the exemplary embodiments illustrate a connection between a conduit end and a particular type of fluid member (a coupling body), such illustration if for explanation purposes only and should not be construed in a limiting sense. The inventions herein may be used to connect a conduit end to any fluid member, such as but not limited to, another conduit end, a coupling component or member, a flow control member such as a valve, regulator, filter and so on. The zero clearance aspect of the present inventions facilitates installing and removing a fitting in a fluid system or circuit by eliminating any need for axial displacement of the conduit end relative to the other fluid member it was coupled to, all while maintaining conduit grip and seal when the fitting is in an installed and completed pulled-up condition. By finger-tight condition is meant that the various parts have been assembled onto a conduit end but in a fairly loose or sometimes snug condition achieved by the rather low manual assembly force or torque. By ‘completed pulled-up condition’ is meant that the fitting has been tightened onto a conduit end to complete a connection between the conduit end and another fluid member, with an established conduit grip and seal. Between finger-tight and completed pulled-up condition may be intermediate pull-up and assembly steps as the fitting is being tightened. Also used herein is the term “make-up” or a fitting that is “made-up” which is similar to “pull-up” in that the terms refer to the process of assembling and tightening the fitting onto a conduit end. Reference herein to a ‘subassembly’ or ‘preassembly’ of fitting parts, and derivatives of those terms, refers to two or more parts that may separately be assembled or joined and held together by any convenient arrangement or method as an integral or single unit to simplify final assembly of the fitting by reducing the opportunity for incorrect installation of the various parts. The terms fluid system and fluid circuit are used somewhat interchangeably herein, with a fluid system generally referring to a more complex arrangement for fluid containment, whereas a fluid circuit may be as simple as a conduit connected to another fluid device by a mechanically attached connection. The present inventions are applicable to all different kinds of fluid systems and circuits regardless of the complexity.

The present disclosure also relates to including a sensing function with a mechanically attached connection including but not limited to a zero clearance fitting, assembly or mechanically attached connection for conduits. As used herein, sensing function, and any embodiment of a sensing function in a ‘sensor’, is intended to be construed in its broadest context as the capability, for example, but not limited to, sense, detect, measure, indicate, report, feedback or collect, or any combination thereof, information, condition, status, state or data relating to the fitting or assembly, one or more of the fitting or assembly components, members or parts, and/or the fluid contained by the fitting or assembly. By sensing fluid contained by the fitting is meant sensing the fluid within the boundaries of the fitting, as distinguished from a sensor or sensing function downstream or upstream of the fitting assembly. The sensing function may be realized by a sensor that is either wetted or non-wetted or both. A wetted sensor is one having at least a portion thereof exposed to the fluid contained by the fitting or mechanically attached connection, while a non-wetted sensor is one that is isolated from contact with the fluid.

While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention, the inventions instead being set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.

With reference to FIG. 1, a first embodiment of one or more of the inventions is presented. An assembly 10 for mechanically attaching or connecting a conduit end C to another fluid member is illustrated. The assembly 10 is also referred to herein as a mechanically attached connection or fitting, but the term fitting is intended to be broadly construed as any arrangement by which a conduit end may be mechanically attached or connected to another fluid component. For reference purposes only, the conduit C has a central longitudinal axis X. Reference herein to ‘axial’ movement or displacement and ‘radial’ movement or displacement is made with respect to the axis X.

The assembly 10 may include a first coupling member or component 12 and a second coupling member or component 14. The coupling components may be any suitable arrangement by which the assembly 10 is installed with conduit grip and seal on the conduit end C. For the FIG. 1 embodiment, the first coupling component 12 may be realized in the form of a female threaded nut, and the second coupling component may be realized in the form of a male threaded body. Typically, a coupling member in the form of a ‘body’ receives the conduit end, typically but not necessarily in a conduit socket. However, in the case of zero clearance fittings as taught herein, the body 14 provides a zero clearance seal surface as will be described below and does not receive the conduit C end. However, the body 14 may have end configurations such as at 16 that do accept a conduit end. Therefore, for purposes of this disclosure we consider a body to be a coupling member that is joinable to another coupling member such as a nut. A coupling member in the form of a ‘nut’ is joined to the body to tighten or pull-up the fitting to a made condition with proper conduit grip and seal, with the nut typically including a drive surface that engages the conduit gripping member during pull-up or may alternatively engage a drive member that engages the gripping member. These components (such as the nut and body for example) are ‘coupling’ in the sense that they can be joined together by relative axial movement with respect to each other, and tightened so as to install the assembly 10 onto the conduit end C so that the assembly 10 grips the conduit to prevent the conduit from loosening under any one or more environmental stresses such as temperature, pressure, strain and vibration to name a few examples. The assembly 10 also provides a seal against loss of fluid. The fluid that is carried by the conduit C may be gas, liquid, a combination thereof or any other fluid medium. The assembly 10 may find typical application in making connections within an overall fluid system. It should also be noted that one or both of the coupling members may in practice be part of or integral with a fluid component, and not necessarily a discrete component as illustrated herein. For example, the body 14 may be integrated or associated with another device or structure, such as a fluid control device such as a valve or valve body, flow meter, tank, a manifold or any other fluid component to which a conduit is to be attached.

The coupling body 14 may itself be considered a fluid member that is connected to the conduit end C, or may include an end configuration 16 that may be further connected to another part, such as a fluid component, another conduit end and so on. As shown, the end connection 16 of FIG. 1 may include a male threaded end 18 of a conventional tube fitting body, but any end connection configuration may be used as needed to connect the conduit end C into the fluid system or to another fluid member.

Although this embodiment provides for a threaded connection between the first and second coupling components 12, 14, threaded connections are only one of the many available choices. Alternatives include but are not limited to clamped or bolted connections. The type of connection used will be determined by the nature of the force needed to secure the assembly 10 to the conduit end in a fluid tight manner. Generally speaking, a fitting such as illustrated in FIG. 1 may be used for a flareless end connection, meaning that the conduit cylindrical shape is not flared as a processing step prior to connection to another fluid member (although the conduit may plastically deform during the installation process). The conduit end does not require any particular preparation other than perhaps the usual face and debur process for the end surface C1 (FIG. 2). In still a further alternative embodiment, the male and female threading may be reversed for the first and second coupling components.

The first coupling component 12 and second coupling component 14 may include wrench flats 20, 22 respectively to assist in joining and tightening the assembly 10 together during pull-up of the fitting. Relative rotation between the coupling components 12, 14 may be used to tighten and loosen the fitting as appropriate.

The body 14 may include a central bore 24 having a diameter that is about the same or the same as the diameter of inside cylindrical wall 26 of the conduit C. For most connections, although not necessarily required in all cases, the bore 24 and conduit C are aligned and assembled in a coaxial manner along the axis X.

The second coupling component 14 further includes a first end face or facing surface 28 at an inner end portion 30 thereof. This end face or facing surface 28 presents a seal surface 32 for purposes which will be more fully explained herein below. The seal surface 32 in this embodiment comprises a generally planar face seal surface, however, other seal surface configurations may be alternatively used based on the type of seal that will interface with the seal surface 32. For example, in the embodiment of FIG. 1, the seal surfaces may include recesses (not shown) that help to align the beads of the seal element 48 during assembly and tightening. From FIG. 1 it will be appreciated that when the first and second coupling components 12, 14 are separated, for example after the fitting 10 has been installed on a conduit end, a simple radial movement or displacement may be used to undo the assembly 10, or in other words to separate the conduit end C from the body 14. This configuration thus achieves a zero clearance connection because the fitting components can be separated without need for axial movement of the conduit C relative to the body 14. In various embodiments, though not necessarily required in all cases, the zero clearance seal is axially separated or spaced from the conduit gripping member, particularly the region where the conduit gripping member indents or otherwise grips the conduit outer surface. Accordingly, the seal that is made at the facing surface 28 is referred to herein as a zero clearance seal, and the assembly or fitting 10 is referred to herein as a zero clearance assembly or fitting. More generally, a zero clearance seal arrangement comprises those parts that together form a zero clearance seal when the fitting is pulled up. In this first embodiment then, a zero clearance seal arrangement may include a face seal insert (40, see below), a seal element such as a gasket for example (48, see below) and one of the coupling components, in this example the body 14. But many alternative embodiments may use different parts and different configurations and shapes to effect a zero clearance seal. In an alternative embodiment, the beads may be provided on one or both of the planar facing surfaces, rather than on the gasket, and the gasket may have flat planar surfaces. Additionally, a zero clearance fitting is provided wherein after disassembly the gripping member remains on the conduit, thus facilitating re-makes of the fitting 10 (a re-make refers to subsequent make-up or pull-up of the fitting after a prior installation of the fitting on a conduit end).

With reference to FIGS. 1 and 2, the assembly 10 may further include one or more parts that may be used to effect conduit grip and seal. A conduit gripping member 34 may be provided to grip the conduit C against an outer surface C2 thereof. For higher pressure applications it may be desirable for the gripping member 34 to indent, cut or bite into the conduit outer surface C so as to provide a strong gripping pressure and resistance to the conduit C backing away under pressure and potentially compromising fluid tight seals within the fitting 10. However, in lower pressure applications the gripping member 34 may be designed to adequately grip the conduit without actually indenting or cutting the conduit surface C2. In addition to providing an appropriate gripping force on the conduit C, the gripping member 34 may also provide a primary or secondary fluid tight seal against the conduit external surface C2 to protect against loss of fluid from the assembly 10. Therefore, as understood herein, a conduit gripping member is any part or combination of parts that, upon complete pull-up of the fitting, grips the conduit against pressure, vibration and other environmental effects, and optionally also may provide a fluid tight seal.

A drive member 36 may be used to assist in applying the needed force to the conduit gripping member 34 during pull-up of the fitting so as to cause the gripping member 34 to deflect or otherwise deform (from its unstressed condition such as in FIG. 1) to grip and optionally seal against the conduit C. In alternative applications, the drive member 36 may not be needed, and an interior surface such as a drive surface 38 of the first fitting component 12 may be used (with additional suitable modifications to the gripping member 34 and seal member 40) to drive the gripping member 34 into gripping engagement with the conduit C.

A face seal member or insert 40 may be used to assist or in cooperation with the driving member 36 in causing the gripping member 34 to grip and optionally seal against the conduit C. The face seal member 40 may optionally provide another primary or secondary seal area where the gripping member 34 engages with an interior surface 42 of the face seal member 40. The face seal member 40 is referred to herein as a seal member because a significant though optional aspect of that component is to provide an end face 44 that presents a second seal surface 46 that faces the first end face 28 and first seal surface 32 of the second coupling component 14. In this exemplary embodiment the seal surfaces 32, 46 are generally flat planar facing surfaces and function as face seal surfaces, in that the fluid tight seal areas are presented in the generally planar surfaces 28, 44. Again, the face seal surfaces 32, 46 may be configured as needed to conform to the shape or geometry of an intermediate seal element 48. In many embodiments, the face seal member 40 may be realized in the form of a gland or body having an appropriate geometry and configuration to present a seal surface to one side of the seal element 48.

With reference to FIGS. 2 and 4, the seal element 48 may be realized in any form that is suitable to provide a zero clearance seal between the conduit gripping member 34 and the second coupling member 14. One example of many is a seal configuration in which a face seal is provided between seal surfaces 50, 52 of the seal element 48 and facing seal surfaces 32 and 46, so as to form a zero clearance seal when the fitting 10 is adequately pulled-up.

In the exemplary embodiment of FIGS. 2 and 4, the seal element 48 may be realized in the form of a face seal gasket of conventional or special design, or as another alternative as shown, have a generally flat, thin washer-like body 54 with an annular sealing bead 56, 58 on either side and facing their respective face seal surfaces 46, 32. Preferably, the relative hardness between each sealing bead 56, 58 and its respective facing surface is such as to promote a good seal when the parts are axially compressed together. Whether the seal surfaces 50, 52 are harder than or softer than the respective facing surfaces 46, 32 is a matter of design option.

The seal element 48 need not have the sealing beads 56, 58 but instead may be flat or may have other features and shapes to promote a good face seal and zero clearance. As another alternative, the beads may be formed on the facing surfaces 44, 28. Other alternatives include but are not limited to using a seal element that is all metal, non-metal or a combination thereof. For example, an elastomer or plastic material may be included with the seal element 48 or with the facing surfaces 28, 44, or both, as needed and as compatible with the system fluid.

With continued reference to FIGS. 2 and 4, the seal element 48 may include a radially tapered collar portion 60 that forms a socket or recess 62. This socket 62 may be used to provide a locator position for the conduit end C1. The socket 62 is defined in part by a tapered and inwardly recessed wall 64 against which the conduit end C1 may abut to indicate to the assembler that the conduit is fully inserted into the fitting 10. The seal element 48 also may include a through passage 66 that is circumscribed by an interior cylindrical wall 68. The diameter of the wall 68 as well as the geometry and material of the seal 48 may be selected so that upon complete pull-up of the fitting, the wall 68 forms a bore line or near bore line continuity between the conduit cylindrical wall 26 and the body central bore 24, so as to reduce entrapment areas at the connection. The tapered wall 64 and cylindrical wall 68 converge at an annular edge 70. This edge 70 may be used to provide a seal area against the conduit end C1 if needed, either as a back-up seal for the bead 56 and the gripping member 34, or as a primary seal.

In the illustrated exemplary embodiment of FIGS. 1-3 and 5, and with particular reference to FIG. 3, the conduit gripping member 34 may be realized in the form of a conically shaped body 72 which in some respects may be comparable to a spring washer. Accordingly, the body 72 may include a central opening 74 that is defined in this example by a radially inner cylindrical wall 76, and that allows the conduit C to be slid there through during assembly of the fitting 10. A common example of a spring washer geometry is a Belleville spring, although such geometry is only exemplary. Belleville springs generally are used to provide a live-load or bias against a surface in a direction along a central longitudinal axis of the spring, in terms of FIG. 1 in a direction that is parallel to the axis X. Our concept in one embodiment is to use a spring washer approach to effect conduit grip and optionally a seal by a radial compression against the conduit outer surface C2 brought about when the spring is axially loaded. An axial load against the conduit gripping member 34 causes the spring to deform to a flatter condition, as compared for example to the spring in an unstressed condition, which produces an inward radial compression of the spring against the conduit C. This concept of using a spring washer to effectively grip and optionally seal against an outer surface of a conduit is fully described in International Patent Application number PCT/US2006/024776 published as WO 2007/002576 A2 on Jan. 4, 2007 and fully incorporated herein by reference. A copy of such disclosure is appended to the provisional application referenced herein above.

In the embodiment of FIG. 3, the conically shaped body 72 comprises two generally and optionally parallel frusto-conical walls 80, 82 extend from the radially inner wall 76 to an optional radial extension 84. A typical Belleville spring does not use the extension 84, and the present inventions may be used with such conventional spring designs in many cases. The outer frusto-conical wall 80 and the inner cylindrical wall 76 converge at a front end or edge 86 of the spring washer 72. This front edge 86 may be but need not be a sharp edge, and preferably may be of such configuration and shape as to indent or embed into the outer surface C2 of the conduit when the fitting 10 is pulled up. During pull-up, in addition to the radial compression against the conduit outer surface, there is a slight axial movement of the front edge 86 as the spring begins to flatten. The front edge 86 is also radially directed against the conduit surface by engagement with the tapered or frusto-conical surface 42 of the face seal member 40. These movements cause the front edge 86 to indent or penetrate into the conduit outer surface C2 (see the discussion below relating to FIG. 5). By indenting into the conduit surface, the conically shaped body 72 will exhibit a high gripping strength against any tendency for the conduit C to try to back out of the fitting, especially under pressure. For lower pressure applications, however, it may not be necessary to have a biting or indenting type effect on the conduit. The conically shaped body 72 may have many alternative geometries and configurations to promote the grip and seal functions as needed and as needed for particular overall fitting 10 configurations and designs.

The gripping member 34 initially engages the interior surface 42 of the face seal member 40 down near the conduit surface, as illustrated in FIG. 3 in the finger-tight condition of the fitting. The interior surface 42 is frusto-conical so as to present a camming surface for the conically shaped body 72, and also to provide a limit on the deflection of the conically shaped body 72 during pull-up. The forward or outer frusto-conical wall 80 and the interior surface 42 may define an included suitable angle α, while the rearward or inner spring wall 82 and an outer tapered frusto-conical surface 88 of the drive member 36 may define an included suitable angle β. In many cases, the angles α and β may be the same or nearly the same, but in other cases they may be different, depending on the design and operation of the gripping member 34. The surfaces 88 and 42 cooperate to control deflection of the conically shaped body 72 in a manner desired to achieve the desired grip and optional seal against the conduit outer surface C2. This control of the deflection may be further enhanced with the use of the optional radial extension 84 that engages a corresponding radial extension 90 on the drive member 36. As the drive member 36 is axially moved against the conically shaped body 72, axial movement of the forward edge 86 is restricted by the face seal member 40, and so the conically shaped body 72 begins to flatten, which in cross-section appears as the walls 80, 82 moving towards a more vertical orientation. This causes in inward contraction of the cylindrical wall 76, in other words a decrease in its diameter, thus causing the forward edge 86 to indent or bite into the conduit, and for the cylindrical wall 76 in general to swage against the conduit C2. By swage is meant that the conduit surface is radially compressed to a smaller diameter, with either plastic or elastic deformation. In alternative cases, especially for lower pressure applications, it may be sufficient for the spring wall 76 to be compressed against the conduit to in effect collet with a radial load against the conduit outer surface, even if the compression is not as much as would be considered a swaging action. Because the conically shaped body 72 does not fully plastically deform and stores potential energy as it is flattened, we consider this design to be a live loaded, and further, the design allows for re-make of the fitting 10, in other words, a fully tightened fitting may be untightened and then re-made with the same resulting conduit grip and seal as needed. Note further that as system pressure increases, the pressure force tends to push the conduit back out of the fitting 10 (as viewed in FIG. 1, from right to left for example). For designs in which the conically shaped body 72 convex side faces the high side system pressure, this tendency for the conduit to attempt to shift out of the fitting results in the conically shaped body 72 becoming even more compressed, causing the conically shaped body 72 to indent further into the conduit and also grip the conduit surface tighter. We call this action an energized conduit grip because the gripping strength increases with increasing system pressure.

It should be noted that while the gripping member 34 illustrated herein is a spring washer type configuration, such is not required, and other annular ring-like conduit gripping and sealing members may alternatively be used.

The face seal member 40 may include an optional cylindrical extension 92 that extends rearward of the conduit gripping member 34, and shrouds about the conduit gripping member 34 and a portion of the drive member 36. The rearward extension 92 may include a hook 94 or similarly functioning and somewhat flexible member that can snap over a back end 96 of the drive member radial extension 90. This arrangement may be used to couple the drive member 36, the conduit gripping member 34 and the face seal member 40 together as a unified subassembly or preassembly 98 (FIG. 1) that may be use to simplify assembly or field use of the fitting 10 so as to reduce chances of improper installation. Techniques other than a clip together arrangement may be used to hold the parts together as a subassembly 98. A subassembly may also include additional parts or fewer parts as needed. For example, the seal element 48 may be included in a subassembly. Another alternative, in some cases the drive member 36 may not be needed, but rather the surface 38 of the nut may be used to drive the conically shaped body 72 against the face seal member 40. In such an alternative, the conduit gripping member 34 and face seal member 40 may be joined as a subassembly or optionally may include the seal element 48 as part of the subassembly. In any case, a subassembly of selected parts that has been fully tightened onto the conduit end will remain on the conduit end after disassembly, loosening, uncoupling or separation of the nut 12 from the body 14.

The cylindrical extension 92 may also include an inner end surface 99 that optionally engages the nut drive surface 38 with a camming action that causes inward radial deflection of the hook or end 94 (see FIG. 5 also). This causes the hook or end to be crimped or compressed against the drive member 36, for example an optionally tapered outer surface 36 a of the drive member. This assures that when a tightened fitting is subsequently loosened or disassembled, the face seal member 40 may remain assembled with the drive member 36 and gripping member 34 as a subassembly 98 on the conduit end.

The drive member 36 may further include an optional rearward cylindrical extension 100 that engages the nut drive surface 38 with a camming action that causes the extension 100 to inwardly deflect or crimp against the conduit outer surface C2 (see FIG. 5). This crimping may optionally include indenting into the conduit but is not required. An optional lubricating material, for example a resin or lubricant 102, such as for example, ultra-high molecular weight (UHMW) polyethylene or UHMW-PE, may be initially placed in the pocket 104 defined by the rearward extension 100. After complete pull-up, the lubricating material is squeezed or displaced into the contact region between the crimped extension 100 and the conduit surface C2. The lubricating material serves to reduce the effects of abrasion and fretting of the conduit surface that may occur as a result of vibrations and bending moments in the conduit.

With reference to FIG. 5, we illustrate an exemplary configuration of the fitting 10 in a fully pulled up and tightened condition. It will be noted that the gripping member 34 is somewhat flattened sufficiently to achieve the desired conduit gripping force by swaging in the region 106 the now smaller cylindrical wall 76 onto the conduit. In some cases this may include forming a shoulder 108 by biting into the conduit surface. This shoulder 108 will press against the front edge 86 of the gripping member 34 in response to pressure which will help prevent the conduit from backing out, and as pressure increases will cause the gripping member to grip even tighter due to further flattening of the gripping member 34. The rearward cylindrical extension 92 of the face seal member 40 has been crimped over the drive member 36, and the rearward cylindrical extension 102 has been crimped onto the conduit, with the lubricating material 102 displaced into the crimped region. The seal element 48 has also been axially compressed between the facing seal surfaces 32, 46 so that the beads 56, 58 form zero clearance face seals therewith. The beads 56, 58 are illustrated with an exaggerated indenting in to the surfaces 32, 46 for ease of understanding. In all the drawings herein, various gaps, spaces and alignments may be somewhat exaggerated for ease of illustration and clarity.

The indented gripping member 34 thus provides grip and seal along the outer conduit surface (for example in the region generally indicated with the numeral 106), the gripping member 34 also provides a seal against the face seal member surface 42 as in the region generally indicated with the numeral 107, and the seal element 48 provides zero clearance seals 109 with the face seal member 40 and with the body end portion 30. These seals provide a fully sealed connection between the conduit end C and the fluid flow path through the body 14.

In order to further increase the pressure rating of the fitting 10, various parts or surfaces may be treated to be surface hardened as compared to the core material. One exemplary suitable process is low temperature carburization which produces a hardened surface that is substantially free of carbides in stainless steel alloys, however, other hardening processes including work hardening and non-low temperature carburizing, nitriding and others may be used as needed based on the desired hardness and corrosion resistance properties needed for a particular application. For example, for a stainless steel fitting 10, it may be desirable to surface harden the beads 56, 58 or the seal surfaces 50, 52 (FIG. 4). It may also be desirable in some designs to harden the entire surface of the conduit gripping member 34, or alternatively the inward portion 110 (FIG. 3) that will indent into and compress against the conduit C. This may be especially useful when the conduit comprises a hard alloy material, such as 2205 or 2507 duplex stainless steel, to name a few of many examples. It may also be desirable in some applications to harden the outer portion 112 of the gripping member 34 (FIG. 3), because just as the inner diameter of the spring washer 72 tends to decrease as the spring is flattened, the outer diameter tends to increase. By hardening the outer portion 112 this tendency to increase the diameter of the spring washer 72 will be lessened. The fitting may also be designed so that the outer rim 114 of the spring washer 72 engages and is radially constrained by the inner surface 116 of the rearward cylindrical extension 92 of the face seal member 40.

During pull-up, the nut 12 axially advances, relative to the fitting body 14, and somewhat flattens the conduit gripping member 34 to indent into the conduit surface, and also effects the radial face seal between the face seal element 48 and the face seal member 40 and the body 14. The body 14 may be, for example, a standard SAE face seal design that would normally accommodate, for example, an o-ring face seal. The face seal member 40 has an opposite surface 42 adjacent to the spring 34, having an angle α with the free and non-flexed conduit gripping spring (in a finger-tight condition such as FIG. 1), and participates with the flattening of the conduit gripping member 34 during pull-up. Opposite the conduit gripping member 34 is the drive member 36 such as a gland, likewise having an appropriate surface 88 (FIG. 3) adjacent to the conduit gripping member 34 with an angle β, which also participates with the flattening of the spring during pull-up while the pull-up also effects the face seal.

The face seal member 40 has the optional rearward extending cylinder 92 that shrouds about the conduit gripping member 34 and much of the drive member 36. The end of the rearward extending cylinder 92 optionally has a radially inward hook that snaps over a radial shoulder 90 on the drive member 36. When snapped together, the drive member 36, gripping member 34, and face seal member 40 form a sturdy cartridge sub-assembly 98 that can be handled, stored, and inventoried as a single unit. As such, within this cartridge 98 prior to pull-up, the gripping member 34 is in its free and un-flexed state. When used, the cartridge 98 may be placed in the nut 12 which is then assembled to the body 14. The conduit end is inserted into the end of the nut 12, through the cartridge sub-assembly 98, and up against the zero clearance face seal element 48. The nut is advanced to create (a) a sealing grip on the conduit, by virtue of flattening the gripping member 34, and (b) a zero clearance face seal on the body 14. In the course of pull-up, the camming drive surface 38 of the nut crimps the end 94 of the rearward extending cylinder radially and more firmly onto the drive member 36, particularly onto an included surface 36 a on the drive gland. The drive member 36 may have the optional smaller rearward extending cylinder 100 that shrouds about the conduit upon assembly. Within the smaller rearward extending cylinder may be a deposit of resin or other suitable lubricant material 102 applied along the circumference of the inside diameter of the smaller rearward extending cylinder. Upon pull-up, the camming drive surface of the nut likewise crimps the end of this smaller rearward extending cylinder radially and onto the surface of the conduit. The lube material 102 is displaced onto the conduit surface and into the contact zone between conduit and the crimped end of the smaller rearward extending cylinder. This lubed crimping action creates a resistance to potentially damaging effects of fluid system vibration. Should the fitting become disassembled, for maintenance of the fluid system or for other purposes, the cartridge sub-assembly 98 stays fixed on the end of the conduit. The nut, captured on the conduit end by the cartridge sub-assembly, is free to slide back on the conduit. This fitting is said to have a zero-clearance design because the body can then be lifted radially away from the conduit end without having to first pull the conduit end axially out of the body. When the fitting is re-assembled (after fluid system maintenance, for example) the nut is slid back over the conduit gripping cartridge sub-assembly 98 and pulled-up on the body. Fluid seals are re-established on the conduit surface and at the body face seal. This fitting design has the further advantage of tighten-ability. Should the fitting develop a leak (due to any of a number of reasons including insufficient pull-up) the nut can be tightened further onto the body such that the sealing members engage further and shut-off the leak.

As noted, the conduit gripping member 34 may have a basically conical shape, also called a Belleville or Belleville-like spring, which has a central hole 76 or inner diameter through which a conduit can pass. Pressing the spring axially so as to flatten it causes that central hole to decrease in diameter such that its edge indents into the surface of the conduit and grips the conduit in place. Configured in a conduit fitting, the flattening of a gripping spring is accomplished by pulling-up or advancing the nut relative to body such that surfaces adjacent to the gripping spring would impart a toroidal flexure or flattening of the gripping spring. These adjacent surfaces start out having an angle α and β with the free and non-flexed conduit gripping spring, touching the spring generally at its radially inner most convex surface, and at its radially outermost concave surface. The gripping spring is configured in the conduit fitting with the convex side toward the source of system fluid elevated pressure. The gripping spring maintains some amount of convexity toward the source of pressure, even after fitting pull-up. As that pressure attempts to push the conduit out from a pulled-up fitting, the inner diameter of the conduit gripping spring embeds deeper into the conduit surface. This provision of a greater grip in response to a greater pressure load to push out the conduit is called an energized conduit grip, a grip that increases to meet an increased conduit gripping requirement due to increasing system fluid pressure.

Embodiments that use a spring-like washer for the conduit gripping member 34 may be used to effect various advantages for the fitting designer. The spring-like member 72 may be tightened to a fully pulled-up condition as in FIG. 5 with a rather short stroke or displacement of the nut 12 relative to the body 14. For example, the embodiment of FIG. 1 may be fully made up with only a half-turn or even a quarter-turn of the nut relative to the body. The use of the generally flat gripping member(s) 34, even if more than one is used in a stacked configuration, provides a compact fitting design. The controlled deflection of the spring also facilitates the use and design of these fittings for thin walled conduits, as well has heavy walled conduits.

Turning now to FIG. 6, we further contemplate as one of our inventions the realization of a ‘smart fitting’, meaning that a fitting or assembly for a mechanically attached connection includes a sensing function that may provide information or data to an analytical function or process about the health, properties, assembly, condition and status of the assembled fitting, one or more of the fitting parts, the fluid contained by the fitting, or any combination thereof. In the present disclosure, an embodiment as illustrated in FIG. 6 includes a sensing function that is incorporated into or otherwise associated with the seal element 48′ that is provided to form a zero clearance seal for the fitting 10. We use the prime (′) notation in FIG. 6 for the seal element because the basic configuration and function of the seal element 48′ may be but need not be the same as was used for the embodiments of FIGS. 1-5. As will be readily apparent from the further discussion below, additional or alternative sensing functions may be introduced into the fitting 10, including many different ways to structurally introduce sensing functions in the fitting.

The present inventions are not limited to any particular fitting design or configuration, and also are directed to the idea of introducing into or including with such fittings a sensing function. Due to the sometimes highly complex and numerous uses of fittings in a fluid system, it may be desirable to be able to sense one or more conditions, or collect data and information, regarding the assembly, performance or health of a fitting or the fluid contained by a fitting or both. With so many fittings already in use, easily numbering in the billions, the present inventions provide apparatus and methods for introducing sensing functions into an existing fitting design, an installed fitting design, or providing a sensing function as part of a new fitting or fitting installation, repair, retrofit or as part of a maintenance operation. With the ability to provide ubiquitous and facile installation of a sensing function with a fitting, the fluid system designer may develop all different types of control and monitoring systems 128 to utilize the data and information collected or obtained right at the fitting site, including as needed on a real-time basis. The control and monitoring system or circuit 128 may be conveniently disposed outside the fitting, even in a remote location, and use wired or wireless communication links with the sensor to receive the data and information provided by the sensor. Alternatively, the circuit 128 may be integrated with the fitting itself, such as on an exterior surface for example. By “remote” is generally meant that the circuit 128 is away from the fitting, and may be at a distance from the fitting, but the term is not intended to imply nor require that it must be a great distance or even beyond line of sight, although in some applications such longer distance communication may be desirable, either in a wired or wireless manner. Some sensors may be interrogated by circuits that are handheld within a close remote location or range such as a foot or less for example. An RFID tag is a common example of such a device.

A fitting with a sensing function can be considered a ‘smart fitting’, meaning that a fitting or assembly for a mechanically attached connection includes a sensing function that may provide information or data to an analytical function or process about the health, properties, assembly, condition and status of one or more of the fitting components, the fluid contained by the fitting, or both. In the present disclosure, the exemplary embodiments as illustrated herein include a sensing function that is incorporated into or otherwise associated with a component or part or member of the fitting, or added to a fitting by means of a sensor carrier or substrate that is provided to position a sensing function in the fitting to perform its designed function.

Although in the FIG. 6 embodiment the sensing function is associated with the seal element 48′, those skilled in the art will readily appreciate that one or more sensors and sensing functions, whether wetted or non-wetted type sensors, may alternatively or in addition to the seal element sensor, be associated with other fitting members such as, for example, the drive member 36, the face seal member or gland 40, the nut 12, the body 14, the conduit gripping member 34 or even the conduit C. As an example, we show a sensor 120 c associated with the face seal member or gland 40 (FIG. 6). The seal element 48′ does provide a simple and fast way to introduce a sensing function into a fitting, whether the fitting is a new assembly, an assembly already installed in a fluid system, or for retrofit, repair or maintenance. Use of installable sensing functions allows a designer to provide a common fitting design that can be made “smart” simply by introducing the sensing function into an installable component such as the seal element for example. For example, even after a fitting has been installed into a fluid circuit, the fitting can be made smart by introducing one or more sensors into the fitting, can have one or more sensors removed, or have different sensors added or removed. For example, internal sensors may be installed by first disassembling a tightened fitting sufficiently to gain access to whatever structure is needed to install a sensor, such as for example swapping out a sensor-less gasket for a gasket having a sensor. Or perhaps the installer may decide to add an external or internal temperature or pressure sensor when it is discovered that temperature or pressure sensing is needed that was not known before at a particular fitting or location in the fluid circuit. These are just a few examples of the many options made available by the inventions herein by having fitting designs that facilitate use of sensing functions with the fitting.Use of a sensing function in an installable part also facilitates postponement of final fitting configuration to the field, which allows for more efficient inventory control since an end user would not need to stock both “smart” and regular fittings. Alternatively or additionally, the sensing function may be incorporated into or integrated with one or more of the various parts of the fitting.

In the exemplary embodiment of FIG. 6, the seal element 48′ may include one or more sensors 120 that are attached to, integrated with or otherwise associated with the seal element 48′. The sensors 120 may take a wide variety of forms and functions. Each sensor 120 may be a wetted sensor 120 a meaning that a portion of the sensor is exposed to the system fluid passing through the fitting 10, or a non-wetted sensor 120 b that is not exposed to the system fluid, or a combination thereof. A sensor may be used, for example, to sense, detect, measure, monitor or otherwise collect information or data about a property or characteristic of the mechanically attached connection, for example, general leakage, conduit bottoming, changes in stress, or vibration to name a few examples; of one or more fitting components such as the coupling components, conduit gripping member(s), seals and so on; and/or the fluid contained by the mechanically attached connection or fitting, or any combination thereof. A wetted sensor 120 a may sense, for example, pressure, temperature, galvanic effects, fluid density, refractive index, viscosity, optical absorbance, dielectric properties, flow rate, conductivity, pH, turbidity, thermal conductivity, moisture, gas or liquid specific properties and so on to name a few examples. Examples for a non-wetted sensor 120 b may include, pressure, temperature, seal integrity, leakage, leak rate, stress and stress profiles, vibration, tube bottoming and so on.

The zero clearance fitting concept herein provides an exemplary structure for optionally introducing a sensing function into a mechanically attached connection. This allows the designer to incorporate a sensing function when needed or to omit the sensing function by either not connecting to the sensor or using a seal element that does not include a sensor in its structure. This allows a sensing function then to be added into a fluid system even after a non-sensor fitting has been installed, simply by replacing the seal element 48 with a seal element 48′ having the sensing function associated therewith. By having a fitting design, whether zero clearance or not, that may optionally receive a sensing function, the end user may decide which fittings will be smart, thus allowing postponement of final fitting configuration to the field. Such postponement may offer significant advantages in terms of inventory management and design optimization for the fluid system.

It should be noted that the locations of the sensors 120 a, 120 b illustrated are exemplary and will be selected as a matter of design choice based on what the sensor function and configuration will be. Additionally, the sensors may be embedded in the seal 48′ body or surface mounted or otherwise attached or integrated with the seal 48′. For example, the non-wetted sensor 120 b may be recessed in a surface such as with a counterbore of the seal 48′ so that it can measure stress or pressure of the conduit end CI against the seal pocket 64 to detect or sense bottoming of the conduit C in the fitting.

The sensors 120 may operate in many different ways, including but not limited to electromagnetic, acoustic-magnetic, magnetic resonance, inductive coupling including antenna, infrared, eddy current, ultrasonic and piezoelectric. The sensors 120 may communicate in a wired or wireless manner with the latter including but not limited to BLUETOOTH™, Wi-Fi, 2G, 3G, RFID, acoustic, infrared, and optical. In the FIG. 6 embodiment, the sensors 120 are wired. Recesses or passages 122 may be formed in the seal 48′ through which wires or conductors or other communication links 124 such as optic fibers may be routed out of the fitting 10. The threaded nut and body connection may include a groove or axial hole or other path 126 positioned below the minor diameter of the threads to allow the communication link to be routed outside the fitting 10 to electronics 128 that will process the sensor information and signals.

The sensors 120 may be incorporated into the seal 48′ by any number of suitable techniques, including but not limited to adhesive, painting, embedding, sputtering, metal injection molding, casting, compression, etched, printed and so on.

There is a wide variety of sensors commercially available today that may be used for various sensing functions. Undoubtedly, many more sensors will be developed and commercialized during the coming years, especially sensors that will have greater functionality, significantly small footprints, alternative installation and integration capabilities and communication functionality. The present inventions contemplate and facilitate the use of such sensors known today or later developed, in fittings as described herein.

Examples of commercially available sensors include but are not limited to the following: Micro-miniature absolute pressure sensor model 32394 available from Endevco Corporation. This is a silicon MEMS device that can be substrate or surface mounted with a conductive epoxy. Another pressure sensor or transducer is the model 105CXX series available from PCB Piezotronics, Inc. These sensors are in very small packages or may be re-packaged as needed for a particular application, and operate with piezoelectric technology. Liquid flow meters such as models SLG 1430 and ASL 1430 available from Sensirion AG. Miniaturized seismic transducers, motion transducers and angular rate sensors available from Tronics Microsystems SA. Tilt and vibration sensors, angle sensors, MEMS inclinometers, MEMS vibration sensors and MEMS accelerometers models SQ-SENS-XXXX, SQ-SIXX, SQ-PTS, SQ-SVS and SQ-XLD respectively, available from Signal Quest, Inc. Piezoelectric accelerometers model TR1BXN having temperature sensing capability, available from OceanaSensor, Virginia Beach, Va. Thermal sensors models LM and STXXX (numerous variations) available from ST Microelectronics. Thermistors, IR temperature sensors, gas tube arresters and varistors available from Semitec USA Corporation. Linear displacement sensors models M, MG, S, SG and NC type DVRTs available from MicroStrain Inc. Proximity switches available from COMUS International.

The above are but a few examples of miniaturized sensors available that may be used with the present inventions. The present inventions facilitate and enable such sensor technology to be incorporated into fittings and mechanically attached connections. Reference may be made to the manufacturer's web pages for additional product information. While the basic product literature may illustrate specific packaging concepts, the sensors may be either repackaged or alternatively integrated with a fitting component or member in accordance with one or more of the various inventions herein.

SENSOR INTEGRATION, WETTED—The sensors 120 may be embedded on the wall surfaces of the seal element 48′. Embedding methods may include but are not limited to resin potting, powder metal sintering, or brazing. Wetted sensors 120 a may be used to monitor fluid system pressure, temperature, and other fluid parameters. As another example, a wetted sensor may be used as a flow sensor. In the flow sensor case, small wetted flow sensors are available from Sensirion. Flow sensors may utilize tuned conduit geometry, such as, for example, including a tuned insert into the fitting. Sensors 120 placed on the wetted surfaces of end fitting tube sockets 64 may also be used to monitor tube bottoming and extent of fitting pulled-up condition. For example, a proximity sensor may be used to detect conduit bottoming or also position of the conduit gripping device or devices to verify pull-up. A wetted sensor can be paired with another sensor (not shown), a non-wetted sensor for example, to facilitate a wireless communication from the first sensor to the other sensor. In other alternative embodiments, wireless wetted sensors may be disposed or integrated with wetted surfaces of the various fitting components, and wirelessly communicate through a wall of the component. This may avoid the need to breach the pressure containment structure of the fitting. But in lower pressure or benign applications, wired sensors that do breach the pressure containment structure may be used. This concept may be applied not only to non-metal components, but also metal components including but not limited to 316 stainless steel. The component material will in part determine the wireless frequency needed, along with the thickness of any wall that the wireless signal must penetrated to be picked up by appropriate electronic circuits that receive and process the wireless signals. As still another alternative, miniature microphones and accelerometers from Akustica may be used in the fitting to detect vibration, leakage or the onset of leakage when variations in the acoustic signatures are detected.

SENSOR TECHNOLOGY—The sensors 120 may comprise a film that is pressure sensitive and changes color with changes in pressure. Photonics sense the color, the indication of pressure, and an optic fiber or other device may be used, for example, for sensor signal transmission to the electronics 128. The sensors 120 may alternatively comprise a force sensitive molecular structure which has a characteristic resonance that is proportional with applied force. That resonance can be detected by a remote scanner for example, such as a RF wand. The sensors 120 may alternatively comprise a dual diaphragm for detecting a spaced differential of a physical property (e.g. pressure differential, strain differential, capacitance). A common detection technique may be use of photonics that sense both diaphragms and detects a response difference (reflection, refraction, or intensity shift) proportional to physical property differentials or change in the diaphragms.

The sensors 120 may be integrated onto the wetted surfaces of the generally circular ring or hoop-like seal element 48′. The sensors 120 may be integrated onto the seal 48′ inside diameter surfaces or on radial surfaces that when assembled in the fitting 10 will be wetted by system fluids. The sensor elements may be laminated, printed, attached, adhesively applied or equivalently applied or otherwise applied directly to the seal 48′ surfaces. The seal 48′ may comprise a split-ring assembly or seal insert to enable direct printing or applying of sensor elements to the seal element inside diameter surfaces. Where axial orientation of the sensor is important, for example sensors for fluid flow, these seal inserts may be keyed to axially differentiated slots or grooves on the seal. The seal 48′ may be keyed directionally using counterbores, circumferential shoulders, or the like to match directionally keyed structures on the fittings, particularly face seal fittings. The sensors 120 that are integrated into the seal 48′ may be hard wired connected to the electronics 128 or other sensors or both, and thus may comprise leads or equivalent to external surfaces to hard wire the sensor from outside the containment of system fluids. Such leads form a composite with the seal such there is no compromise of system fluid containment or seal integrity. Sensors integrated into the seal 48′ may comprise leads or equivalent to provide external antenna for the sensors. Here also, such leads form a composite with the seal such there is no compromise of system fluid containment or seal integrity. Sensors integrated into seals, whether fully passive or powered by built-in battery or fuel cell, may alternatively comprise no leads to external surfaces, and thus no compromise of system fluid containment or seal integrity.

The inventions herein include methods for mechanically connecting a conduit to another fluid member, with the methods fully set forth above in the description of the exemplary embodiments. One such method comprises connecting a conduit to a fluid member by forming a conduit gripping connection and a zero clearance seal in an exemplary manner as set forth above. In another embodiment, the method may include providing a sensing function that is associated with the zero clearance seal.

The electronics 128 (FIG. 6) may be operably coupled to the sensors 120 in many different ways, including wired and wireless connections. Wireless connections may include electromagnetic coupling such as by antenna, or optical coupling, acoustic and so on. The specific circuits used in the electronics 128 will be selected and designed based on the types of sensors 120 being used. For example, a strain gauge may be used for a non-wetted sensor 120 b, and the strain gauge will exhibit a change in impedance, conductivity or other detectable characteristic or condition. The electronics 128 may provide a current or voltage or other energy to the strain gauge, across a wired connection or wireless connection for example, so as to detect the strain gauge condition of interest. Similarly, the electronics 128 may interrogate or detect a temperature or pressure sensor condition, or the electronics 128 may receive signals transmitted from the sensor that encode or contain the information or data of interest produced by the sensor. These are just a few examples of the wide and extensive variety of sensors and electronics that may be used to carry out the inventions herein.

With reference to FIG. 7, the drawing illustrates one example of many different types of a fitting 2010 that may be used with one or more of the present inventions. In particular, FIG. 7 illustrates a flareless compression fitting that uses a smart fitting concept of incorporating one or more sensors into the fitting. Such uses of sensors as illustrated in FIG. 7 may also be used with the zero clearance type fittings described herein. The fitting 2010 typically includes a nut 2016 that may be joined with a body 2012 such as, for example, with a threaded connection 2014, 2018. One or more compression type ferrules 2020, 2022 may be used to seal and hold a conduit end such as a tube or pipe end so as to form a leak tight flow path from the conduit to another flow path, in this case through the body 2012. The fitting illustrated in the drawing is commonly referred to as a female fitting in that the body 2012 is a female threaded component that joins with the male threaded nut 2016. Alternatively, as is well known, male fittings are commonly used that have a male threaded body and a female threaded nut. Non-threaded connections may alternatively be used as well. In accordance with the present disclosure, one or more of the fitting components including the body, nut, the ferrules and the conduit end, may be provided with one or more of electrical, electro-magnetic or electronic capability, such as for example a sensor or element 2100, that facilitates manufacture, assembly or use of the fitting. The component 2100 may be surface mounted, embedded, etched or otherwise associated with a fitting component as needed for a particular application.

SENSOR INTEGRATION—(a) Sensors are applied to the surfaces of fitting components—e.g. to the fitting body, ferrule or ferrules, nut, tube adaptor, or tube end. Application methods for applying sensors can include sticking, gluing, painting, plating, or in coatings of any type. (b) Sensors are embedded in fitting components. Embedding methods can include resin potting, powder metal sintering, or brazing. (c) Sensors are made concurrently integral to fitting components, as the components are manufactured. Such concurrent methods can include metal injection molding, casting, or compression and injection molding in the case of plastic fitting components. Concurrent methods can also include sensor placing or embedding at regular intervals on or in bar stock, such that one or more sensors remain in each machined component. (d) Sensors may be chipless in the sense that they are printed, etched, sputtered, or likewise marked onto fitting components. Such marking methods can include application of sensor circuitry material to the component, making use of the component material substrate. Marking methods may not necessarily use silicon applications. Marking methods can also include use of electrical conductor altering properties of a diffusion modified near surface of the component, doping elements within the component alloy or material, or dispersed or localized second phases within the component material. (e) Sensors are integrated with fitting design. Such integration can include access ports to aid sensor powering or data query, whether by electro-magnetic effects, acoustic-magnetic effects, magnetic resonance, inductive coupling, IR, eddy current, surface acoustic waves, or ultrasonic.

SENSOR APPLICATIONS—(a) Sensors applied to components provide component history, QA/QC information, source tracing back to the manufacture of the raw material melt or equivalent. (b) With use of a central registry, sensors guard against and detect incidence of component intermix or component counterfeiting. (c) Sensors provide data specific to the fitting—e.g. product ratings, codes and standards, material and fluid compatibilities, and installation instructions. (d) Sensors provide feedback on the condition or success of fitting installation in a fluid system—e.g. ferrule order, tube bottoming, turns of the nut. Such feedback can be coupled with visual, color codes, vibrating, audible or voice devices for immediate access to fitting specific data and indication of installation condition. Such feedback can also include both self diagnostics and suggested remedies. (e) In use, sensors provide indication of changes in the installation—e.g. nut turning, tube slippage, component removal, corrosion effects, any other impending dysfunction, as well as successful ferrule or component response adapting to a changing fluid system. (f) In use, sensors provide measurement of fluid system and fluid state parameters—e.g. pressure, temperature, fluid properties, fluid flow rate, or system vibration. Sensors can relate such measurements to applicable agency codes, standards, product ratings, and can warn if exceeding allowed ratings or levels. Fluid flow methods can include IR signal processing. (g) In use, sensors detect fluid leaks and provide indications of leak rate, as well as confirmation of successful fluid sealing. Leak and seal detection methods can include ultrasonic signal processing.

SENSOR TECHNOLOGY—(a) Sensor are wired or wireless. Sensors can include the fluid system tubing in the sensor circuitry. If wired, this can include use of fluid system tubing for sensor powering or signal transmission. If wireless, this can include use of the system tubing as antenna. In both cases, sensors can use the position of tubing in the fitting as part of circuitry indicating successful tube position during and after installation. (b) Sensors are powered or passive. If powered, sensors can use batteries or miniature fuel cells. They can draw direct external electrical power or draw power through use of electro-magnetic field effects, magnetic resonance, inductive coupling, infrared (IR), eddy current, surface acoustic waves or ultrasonic. Sensors can also draw power from the environment—e.g. changes in temperature, system fluid flow, static charge build-up, system vibration, or galvanic effects of locally dissimilar materials. If passive, sensors are powered by incoming query from an external device. Such queries can use any of the above methods for the continuous powering of powered sensors. (c) Sensors use present or emerging signal processing and communication protocols. If wired, protocols include 4 to 20 m-amps. If wireless, protocols include WiMax, 3G or 2G cellular, Wi-Fi, Bluetooth, Zigbee, Ultra Wide Band, or RFID. Protocols can also include use of mobile phones or equivalent mobile reader devices to collect data and communicate with a central registry. Such mobile reader devices can be integrated into the tools used for fitting pull-up. (d) Sensors are piezoelectric or respond similarly to mechanical deflection or strain. Applied on or in fitting components, sensors respond to fluid system parameters—e.g. pressure, vibration, ultrasonic effects of fluid leaks—as well as extent of fitting pull-up during or after installation.

Smart fitting applications include, as examples:

-   (1) Installed Fitting Health—Sensors in the fitting components     measure conduit and component loads and relative positions as     measures of both initially sufficient and sustained-in-use installed     fitting pull-up. Sensor types include micro-strain, proximity,     vibration/acceleration, ultrasonic and cycle count. -   (2) Installed Fitting Seal Integrity—Sensors in the components of     installed fittings measure incidents of seal leakage of system     fluids. Sensor types include ultrasonic and chemical detectors. -   (3) System Fluid Measurement—Sensors in the components of installed     fittings measure the characteristics of system fluids. Sensor types     include temperature, pressure, flow, density, refractive index,     viscosity, optical absorbance, dielectric characteristic,     conductivity, pH, turbidity, thermal conductivity, moisture and     chemical specie. -   (4) Integrated Sensors—Sensors attach to fitting components by     methods including direct printing or fabrication on the component     surface, on gaskets or inserts that assemble into and between     fitting components. -   (5) Sensor Communication—Sensors are wireless and passive, both     wetted and non-wetted by system fluids. Wetted sensors communicate     through the system fluid containing walls of the fitting components     without antenna or wires that breach the fluid containing walls.     Wetted sensors also have known chemical compatibility, duty cycle     and failure mode. -   (6) Traceability—Sensors (e.g. RFID) in the fitting components     provide fitting and component characteristics including identity,     serialization and code compliance.

With reference to FIGS. 8-10, we illustrate another embodiment of a zero clearance fitting 200. The fitting 200 may include a first coupling member or body 202 and a second coupling member or nut 204 that are joined together during pull-up of the fitting. In this embodiment the body and nut may be threadably joined as with a threaded connection 206. The body 202 may further include a planar end face 208 that also forms or provides a face seal surface for a zero clearance face seal arrangement 210. The body 202 may itself be considered a fluid member that is connected to the conduit end C, or may include an end configuration 216 that may be further connected to another part. As shown, the end connection 216 of FIG. 8 may include a male threaded end 218 of a conventional tube fitting body, but any end connection configuration may be used as needed to connect the conduit end C into the fluid system or to another fluid member. The body 202 may also be integrated into or with another device such as a fluid control device, such as for example a valve, flow mater, tank and so on to name just a few examples.

Although this embodiment provides for a threaded connection between the first and second coupling components 202, 204, threaded connections are only one of the many available choices. Alternatives include but are not limited to clamped or bolted connections. The type of connection used will be determined by the nature of the force needed to secure the assembly 200 to the conduit end in a fluid tight manner. Generally speaking, a fitting such as illustrated in FIG. 8 may be used for a flareless end connection, meaning that the conduit cylindrical shape is not flared as a processing step prior to connection to another fluid member (although the conduit may plastically deform during the installation process). The conduit end does not require any particular preparation other than perhaps the usual face and debur process for the end surface C1.

In many respects, the fitting 200 functions in a similar way to the embodiments of FIGS. 1 and 6. However, rather than a spring type conduit gripping member, the fitting 200 may use a gripping member 220 that is an annular ring like device such as, for example, a ferrule or multiple ferrules. The gripping member 220 may include a continuous cylindrical interior wall 220 a closely received over the conduit C outer surface C2, and that extends completely through the device, or may have various contours, recesses and so on as needed for a particular application. A face seal insert 222 cooperates with the gripping member 220 and the second coupling member 202 to effect conduit grip and fluid tight seals. However, in this embodiment (as contrasted with the embodiment of FIG. 1 for example) the insert 222 is a single piece that performs both the face seal function and receives the conduit end C in a conduit end socket.

The insert 222 may be an annular part having a first interior cylindrical wall 224 and a second interior cylindrical wall 226. The diameter of the first wall 224 is somewhat less than the diameter of the second interior wall 226 so that a shoulder 228 forms a socket into which the conduit end C1 is received. During assembly and tightening (pull-up) of the fitting 200, the conduit end C1 should bottom against the shoulder 228. The insert 222 may also be provided with an annular sealing bead or ring 230 that contacts the planar end facing seal surface 208 of the first coupling member 202. During pull-up of the fitting, the bead 230 is compressed against the seal surface 208 to form a fluid tight seal. The bead 230 may be less hard than the surface 208 so that the bead is somewhat flattened, as illustrated in FIG. 9.

The first and second interior walls 224, 226 may be joined by a somewhat tapered wall portion 232. This causes an inward radial compression of the conduit end C1 during pull-up to help retain the conduit in the socket and also may form a fluid tight seal.

The insert 222 may also include a rearward axial cylindrical extension 234 having an outer surface portion 234 a that engages a tapered surface 236 of the second coupling member 204. Relative axial movement between these surfaces causes a radial inward compression of the extension 234 (see FIG. 9) so that the extension end or lip 234 b is bent or deforms around the gripping member 220 upon complete pull-up. Because the gripping member 220 remains attached to the conduit after pull-up, even when the first and second coupling members are thereafter separated, the insert 222 will remain assembled to the conduit as well. In addition, as the extension 234 slides or cams against the tapered surface 236, the torque required to tighten the fitting 200 will increase significantly, facilitating a pull-up by torque function. Thus, the fitting 200 is amenable to pull-up by torque or pull-up by counting turns of rotation of the second coupling member 204 relative to the first coupling member 202.

The second coupling member 222 may also have a frusto-conical surface 238 which engages a tapered wall 240 of a nose portion 242 of the gripping member 220. Preferably, although not necessarily, the frusto-conical surface 238 is formed at an angle α relative to the longitudinal axis of the fitting 200, with the angle α in the range of about 35 degrees to about 60 degrees, preferably about 45 degrees.

The gripping member 220 may include a reverse tapered outer surface 244 so that when the gripping member 220 is axially compressed into the socket defined by the extension 234, the bent lip 234 b will have adequate room to compress without strongly compressing the rearward portion of the gripping member 220. The gripping member 220 further includes a driven surface or back end 246 that engages with a drive surface 248 of the second coupling member 204 during pull-up.

With reference then to FIG. 9, we illustrate the fitting 200 in a pull-up condition. The gripping member 220 has plastically deformed with a forward edge 250 having indented into the conduit C outer surface to form a shoulder 252. This engagement between the forward edge 250 and the shoulder 252 provides very strong conduit grip against pressure and may also form a fluid tight seal. The conduit gripping member 220 deformation may further include the cylindrical interior wall 220 a deforming to a convex portion 254. The convex portion may be contiguous to the front edge 250 or may be axially spaced there from, but in either case the convex portion 254 swages or collets or accompanies an action that swages or collets against the conduit outer surface (with either plastic or elastic deformation of the conduit as needed) to provide a radial stress into the conduit which isolates vibration effects from the high stress region or stress riser that forms in the area where the front edge 250 bites into the conduit. Still further, the camming action of the gripping member nose portion 242 against the frusto-conical surface 238 produces a metal to metal seal. When the angle α is about 45 degrees, the compression of the nose portion 242 against the camming surface 238 is akin to a coining action.

After the fitting 200 has been tightened, it may be disassembled by simply loosening the second coupling member 204 with respect to the first coupling member 202. Because the conduit end C1 does not extend into the first coupling member 202, when the second coupling member 204 is separated back from the first coupling member 202, the fitting can be separated radially without axial displacement of the conduit relative to the first coupling member, thus making the fitting 200 a zero clearance fitting.

Alternatively, the gripping member 220 need not actually bite into the conduit and there need not be a swage or collet effect produced, such as for fittings that will not be expose to vibration or elevated pressures, for example. As another alternative, various parts or surfaces of parts may be hardened to effect metal to metal seals. For example, the facing seal surface 208 may be hardened relative to the bead 230 which will result in the bead flattening and also produce an effective metal to metal seal. Also, the gripping member 220 may be case or through hardened so that it can bite into hard conduit materials as well as form the seal against the camming surface 238. Any suitable hardening process may be used for the various surfaces or parts, including but not limited to low temperature carburizing, work hardening and so on as are well known to those skilled in the art. The use of hardened surfaces to enhance the metal to metal seals and tube grip may be used with any of the embodiments described herein.

All of the zero clearance exemplary embodiments illustrated or described herein may optionally include one or more sensors or sensing functions, such as for example illustrated in FIGS. 6 and 7 herein, or others, including different positioning of the sensors within the various fitting components.

With reference to FIGS. 10-15, we illustrate additional optional and alternative designs and features for the zero clearance fittings of FIGS. 1 and 10 herein. For clarity and ease of explanation, for these various embodiments we only illustrate the enlarged half view in longitudinal cross-section of the coupling area of the fittings, similar to the views of FIGS. 2, 6 and 10 for example. It will be readily understood by those skilled in the art that each complete fitting is symmetrical about the central longitudinal axis X and may, but not necessarily needs to, have similar first and second coupling member designs as the FIGS. 1, 6 and 8 embodiments, or different designs for the first and second coupling members. We also only show the fittings in a finger tight condition, it being understood that during pull-up the gripping members may deform in a similar way, or alternatively may deform in a manner needed for a particular application. All of these embodiments may also have hardened surfaces or parts as needed, as well as sensing functions incorporated therewith.

In the FIG. 11 embodiment, the fitting 300 may be similar to the embodiment of FIG. 10, and like reference numerals are used for like parts or structural features. It should be noted however, that the exact same parts need not be used for all applications, as demonstrated by the variations of these alternative embodiments. Thus, there is a first coupling member having a facing end surface 208 that functions as a zero clearance face seal surface. An insert 222 includes a sealing bead 230 that forms a zero clearance face seal against the surface 208 upon pull-up. The insert 22 also includes a conduit end socket formed by a shoulder 228. A second coupling member 204 is joinable to the first coupling member such as, for example, with a threaded coupling 206 or other suitable arrangement. A conduit gripping member 220 is provided.

In comparing FIGS. 11 and 10 it will be noted that an additional piece is included, in the form of a retaining cup or ring 302. This retaining piece 302 is a hollow somewhat flexible member that can slideably receive the conduit end C1 and is inserted into the second coupling member 204 before the conduit gripping member 220. The insert 222 includes a modified rearward portion that omits the extension 234 in the FIG. 10 embodiment. The insert 222 includes the frusto-conical camming surface 238, but further includes a notch, recess or groove 304 in its outer surface. The retaining ring 302 at its outer end includes one or more fingers or projections 306 that are received into the recess 304, such as for example with an optional noticeable click or snap. In this manner, in the finger tight condition, or even before the conduit end C1 is inserted into the second coupling member 204, the retaining ring 302 functions to hold the coupling member 204, the insert 222 and the gripping member 220 together as a preassembled component or cartridge. This can greatly simplify final assembly in the field, as the user only needs to mate up the preassembled cartridge with the first coupling component 202 after the conduit end has been inserted (thus providing a two piece fitting as far as the user is concerned, having zero clearance). To further aid in keeping the preassembly together, the retaining ring may optionally have a stiffer rearward body portion 308 that snugly engages into the socket of the second coupling member.

The retaining ring 302 may be a cup like element that is solidly annular, or the fingers 306 may comprise a plurality of extensions from the body 308. The recess 304 may likewise be continuous about the circumference of the insert 22 or may be provided in two or more sections.

In the embodiment of FIG. 12, another zero clearance fitting 350 comprises various parts that may be of similar design to the FIG. 11 embodiment, except that it will be noted that the retaining ring or cup is no longer used. Instead, in this embodiment, an annular retainer or sleeve 352 is provided. This sleeve may be somewhat compressible and fits between the recess 304 and an inner cylindrical wall 354 of the second coupling member 204. The sleeve 352 may provide an interference fit between the insert 222 and the second coupling member 204 so as to retain as a preassembly or cartridge, the second coupling member 204, the gripping member 220 and the insert 222. The sleeve 352 may be made of any suitable material, and may be non-metal as it is not needed for any seal or structural function other than to hold the preassembly together from the factory to the field.

In the FIG. 13 embodiment, another zero clearance fitting 400 comprises various parts that may be of similar design to the FIG. 10 embodiment, except that it will be noted that the rearward extension has been modified. In this embodiment, the insert 222 is provided at its rearward portion with a thin flexible extension 402. The extension 402 may be in the form of an annular continuous cup, or may be realized as one or more fingers or ribs that extend rearward, such as for example, from the frusto-conical camming surface 238. This retaining feature 406 of the extension 402 and lip 404 may include an inward lip 404 that slides over and against the outer surface 244 of the gripping member 220. In this way, the retaining feature 406 may be used to hold the insert 222, gripping member 220 and second coupling member 204 together as a preassembly or cartridge for shipment to the field or end user. For example, there may be provided an interference or snug fit of the gripping member 220 inside the second coupling member 204, or alternatively an adhesive may be used to retain the parts together or other structure may be added to foam the preassembly. Moreover, the insert 222 and gripping member 220 may together be considered as a preassembly.

The FIG. 14 embodiment of a zero clearance fitting 450 is similar in most respects to the FIG. 13 embodiment, except that in addition the gripping member 220 may be provided with a notch or relief 452 in its outer surface 454, that cooperates with the extension 402, and more specifically with the lip 404, to function as the retaining feature 406. In this way, the retaining feature 406 may be used to hold the insert 222, gripping member 220 and second coupling member 204 together as a preassembly or cartridge for shipment to the field or end user. For example, there may be provided an interference or snug fit of the gripping member 220 inside the second coupling member 204, or alternatively an adhesive may be used to retain the parts together or other structure may be added to form the preassembly. Moreover, the insert 222 and gripping member 220 may together be considered as a preassembly.

With reference to FIG. 15, we illustrate another embodiment of a zero clearance fitting 500. This embodiment has many similarities to the embodiment of FIG. 1, but with some significant differences as will be further explained herein. The fitting 500 may include first and second coupling members 512, 514 which may be the same or different from the coupling members 12, 14 of the FIG. 1 embodiment. The coupling components 512, 514 may be threadably coupled as at 515, but may be joined by any other technique as needed. The second coupling member 514 may include an annular zero clearance face seal surface 514 a.

A generally annular face seal member or insert 516 includes a face seal surface 518 on one end, and a frusto-conical surface 520 on an opposite end. The insert 516 further may include a cylindrical interior wall portion 522 and an optional tapered interior wall portion 524. The conduit end C1 is closely received by these interior wall portions. The conduit end C1 after pull-up is radially compressed by the tapered wall 524 and may form a fluid tight seal therewith.

A conduit gripping member 526 that may be an annular ring like device such as, for example, a ferrule. The gripping member 526 may include a continuous cylindrical interior wall 526 a closely received over the conduit C outer surface C2, and that extends completely through the device, or may have various contours, recesses and so on as needed for a particular application. The gripping member 526 also has a rear wall portion 528 that is a driven surface that contacts a drive surface 530 of the first coupling member 512. The gripping member 516 may also include a tapered nose portion 532 that engages and cams against the frusto-conical surface 520 during pull-up of the fitting 500. The gripping device 526 may but need not deform during pull-up in a similar manner to the gripping device of the FIG. 9 embodiment.

A seal member 534 may be disposed between the insert 516 and the zero clearance end face 514. This seal member may be similar in design and function as the seal member 48 in the FIG. 1 embodiment. However, because the insert provides a conduit end socket formed by the cylindrical walls 522, 524, the seal member 534 does not include a radial inward extension, although alternatively it may. The seal member 534 may include first and second annular sealing beads 536, 538 that respectively are compressed against the seal surfaces 514 a and 518.

It should be noted for all the embodiments that use sealing beads and so on, the beads may alternatively be formed on the facing surfaces so that the seal member presents planar seal surfaces. Also, the sealing beads may be in a shape and size that is different from the illustrated embodiments. In still a further embodiment, the insert 516 and the seal element 534 may be formed as a single piece part, similar for example to the embodiment of FIG. 14 herein.

Additional and optional features of the embodiment of FIG. 15 is the provision of a retaining feature 540 in the form of an annular extension 542 rearward from the main body of the seal member 534. This extension 542 may include a lip 544 or similar protrusion that cooperates with a lip 546 formed at one end of the insert 516. This insert lip 546 may be formed as part of providing a circumferential recess or notch 548.

The insert 516 may also include an optional rearward extension 550 from the frusto-conical surface 520, much in the same manner as the extension illustrated in FIGS. 13 and 14 herein. This extension 550 may include a lip 552 that engages with the gripping member 526 so that the gripping member 526, the insert 516 and the seal member 534 may be assembled as a preassembly or cartridge. This preassembly may also be installed in the first coupling member 512 for a two piece fitting construct to be assembled later in the field or by an end user. The gripping member 526 may optionally be provided with a notch (not shown) as used in the embodiment of FIG. 14 to cooperate with the lip 552.

The drive surface 530, as well as the driven surface 528, may be contoured or shaped other than as a frusto-conical shape as illustrated herein to facilitate tightening of the fitting during pull-up. This may apply to all the gripping member designs described herein. In the FIG. 15 embodiment, the drive surface has a first section 530 and a second section 554 with a shallower taper. This additional section may assist in the gripping member releasing from the first coupling member during disassembly. Alternatively, the drive surface 530 may be a single continuous angle surface (not shown).

In the various alternative embodiments described herein with respect to FIGS. 10-15, the fittings will be pulled-up and function in a manner similar to the earlier described embodiments herein, especially as to conduit grip, fluid tight seal, reduced vibration sensitivity, preassembly, postponement, re-make capability and so on.

The inventive aspects have been described with reference to the exemplary embodiments. Modification and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. 

1. Fitting for connecting to a conduit end wherein the conduit has a longitudinal axis, comprising, a first coupling component and a second coupling component that are joinable together, a conduit gripping member and a zero clearance seal arrangement, wherein said conduit gripping member grips an outer surface of the conduit when the fitting is pulled-up, and said zero clearance seal arrangement forms a zero clearance seal at a location that is spaced from said conduit gripping member.
 2. The fitting of claim 1 wherein said first and second coupling components being axially joinable together during pull-up of the fitting to cause said conduit gripping member to grip the conduit and to cause said zero clearance seal.
 3. The fitting of claim 2 wherein said first coupling component comprises a female threaded nut and said second coupling component comprises a male threaded body.
 4. The fitting of claim 1 wherein said conduit gripping member indents into the conduit surface when the fitting is pulled-up.
 5. The fitting of claim 4 comprising a gasket disposed between a first seal surface of a face seal member and a first seal surface of one of said coupling components, said seal surfaces facing each other and forming said zero clearance seal with respective opposite sides of said gasket.
 6. The fitting of claim 1 wherein said gripping member comprises an annular ring.
 7. The fitting of claim 1 wherein said gripping member comprises a ferrule.
 8. The fitting of claim 5 wherein said conduit gripping member and face seal member are adapted to be a joined subassembly prior to installing said fitting onto a conduit.
 9. The fitting of claim 8 wherein said face seal member comprises a cylindrical extension that holds said face seal member and conduit gripping member together as a subassembly.
 10. The fitting of claim 1 wherein said conduit gripping member comprises at least portions thereof that are surface hardened.
 11. The fitting of claim 10 wherein said surface hardened parts comprise carburized stainless steel surfaces substantially free of carbides.
 12. A fitting for conduits, comprising: a conduit end portion, a first coupling component and a second coupling component that are joinable together, a conduit gripping member, and a face seal member disposed between said first and second coupling members, said conduit gripping member indenting into a surface of the conduit to grip the conduit and said face seal member forming a zero clearance seal, when the fitting is made up.
 13. The fitting of claim 12 comprising a gasket disposed between said face seal member and said second coupling component, said gasket forming a zero clearance face seal with each of said face seal member and said second coupling component when the fitting is made up.
 14. The fitting of claim 12 wherein said face seal member comprises a seal surface that seals against a seal surface of one of said first and second coupling members when the fitting is made up.
 15. The fitting of claim 1 wherein said zero clearance seal arrangement comprises a face seal member and seal disposed between a first seal surface of said face seal member and a second seal surface, said first and second seal surfaces facing each other and forming said zero clearance seal with respective opposite sides of said seal.
 16. The fitting of claim 15 wherein said seal comprises a gasket.
 17. The fitting of claim 16 wherein said gasket comprises a flat metal washer-like device.
 18. The fitting of claim 1 wherein said conduit gripping member comprises a Belleville spring with a radial extension at an outer circumference thereof.
 19. The fitting of claim 1 wherein the conduit and said conduit gripping member comprise a stainless steel alloy.
 20. The fitting of claim 1 wherein said conduit gripping member comprises a Belleville spring configuration.
 21. The fitting of claim 1 wherein said conduit gripping member comprises first and second frusto-conical walls extending radially outward and in a first axial direction from a radially inner portion to a radially outer portion, the radially inner portion having an annular conduit indenting edge configured to plastically deform the conduit along a circumferential ring of engagement when the fitting is pulled up to provide a seal between the conduit gripping member and the conduit.
 22. The fitting of claim 21 wherein during pull-up said conduit gripping member is axially compressed so as to partially flatten, reducing a diameter of said radially inner portion to grip the conduit.
 23. A fitting for a fluid conduit mechanically attached connection, comprising a conduit gripping member, a zero clearance seal element and a sensor associated with said seal element to detect a condition or characteristic of a fitting component or fluid contained by the fitting.
 24. The fitting of claim 23 wherein said sensor is one of the following: a wetted sensor, a non-wetted sensor.
 25. The fitting of claims 21 wherein the sensor is integrated with the seal element.
 26. The fitting of claim 25 wherein said seal element comprises an annular face seal gasket. 